1. Field of Invention
At least one embodiment of the invention relates to image processing, in particular, to locating an object in an image.
2. Discussion of Related Art
Image processing is employed in a wide variety of applications in which a system such as a machine vision system processes an image that has been scanned or otherwise been captured in a digital format. The images that are processed may be captured by a camera including a video camera. At least in part as a result of improved digital imaging technology (i.e., digital cameras, etc.), there is an increased reliance on methods for processing images to obtain information that can be used with automated systems. Material handling systems provide one such example.
Often, image processing involves locating one or more objects within the image. Examples include locating the barcode in an image of an item and locating a character string in an image of an item. Once the object is located, the system may then interpret the information provide by the object or otherwise further process the image based on the information. For example, where optical character recognition (“OCR”) is employed, character strings located in an image may be interpreted (e.g., read) after they are located. Where the object is a barcode, the barcode data can be interpreted once the barcode is located.
One known approach to locating objects with repetitive patterns such as barcodes and character strings includes finding aligned regions having similar sizes and intensity, sometimes referred to as “blobs.” However, these approaches are ineffective where separate elements or separate characters, respectively, each touch another object because the blob includes the separate elements within it and the separate elements may not be located using current approaches.
Thus, current approaches are not robust enough to locate objects with repetitive patterns without being provided with an exact description of the object and knowledge of the object's size and orientation. Current approaches are particularly ineffective when the object being searched for is touching another object in the image.